Construction machines or vehicles are equipped with a variety of controllers designed to collect vehicle operating data such as the current location of the machine or vehicle, data representing the accumulated operating hours of the vehicle or machine as may be identified on a service-hour meter, data representing the error history of the vehicle, and the like. A controller of this type installed in a vehicle has a CPU that executes computations, collects the vehicle operating data, and communicates with external servers in accordance with a program stored in an EEPROM (electrically erasable programmable ROM) such as flash memory. A controller installed in a vehicle is connected to an external server to freely communicate with each other via communication means (e.g. the internet) to send the collected data associated with each vehicle to one another. An operator may go to a site and connect his or her personal computer to the controller on the vehicle to read out vehicle operating data.
Certain situations require the installed program to be overwritten such as when upgrading the program; creating error codes specific to each vehicle; and changing a threshold value, and the like.
Japanese Patent Publication H10-212739 (hereinafter Patent Publication 1) discloses a communication data collection network for vehicles comprising: a controller for collecting vehicle operating data and a monitoring device, which is located in a remote location as a server to link the data collection network to the monitoring device that the monitoring device may command the operating data collection controller to overwrite the normal operating data processing program with another operating program. In a normal operating mode, a controller installed in a construction machine collects operating data in accordance with a data processing program which processes the data, and sends the data to the monitoring device when the monitoring device requests the data. During an overwriting mode, the monitoring device sends a new operating data processing program to the construction machine to overwrite the current data processing program in the operating data collection controller associated with the construction machine.
There is a demand to permit overwriting a data processing program in one or more construction machines or vehicles which are interconnected through a common communication system in such a manner that a designated construction machine or plurality of machines can perform normal operating data processing under one data processing program while another group of machines are switched into an overwriting mode for operation under a different data processing program.
Data transmitted between a server (hereinafter “monitoring device”) and construction machines during normal operating data processing typically includes data representative of the current location of the vehicle, a value representing (e.g. accumulated operating hours) displayed on a service-hour meter, an error history of the vehicle, and the like, in which data volume may only constitute several bytes of information. In contrast, data transmitted between the monitoring device and construction machines for overwriting the current program is exponentially larger than the data volume transmitted for normal operations.
For this reason, an inefficiency arises if the same monitoring device is assigned to handle simultaneous operation for normal operating data processing and for overwriting in that the monitoring device in the overwriting mode will monopolize the communication circuit between the interconnected construction machines. This in turn may increase the time required for overwriting, thereby hindering smooth transmission of the vehicle operating data between servers and other construction vehicles during normal operations. This may further cause the vehicle operating condition data (hereinafter referred to as “vehicle condition data”) to be lost in the middle of the communication circuit or received too late. In a worst case scenario, a system crash may occur, adversely affecting normal operations.
The vehicle or machine condition data collected during normal use by construction vehicles or machines contain data that may be crucial to the users of the construction vehicles and machines. An interruption in real time reception of the vehicle or machine operating data by the monitoring device is unacceptable.
Patent Publication 1 does not permit parallel processing of both normal operating data and overwriting data nor does it teach a method of switching between terminals to permit overwriting data in one or more construction machines interconnected to one another through a common communication system.